Abstract
Myoglobin-mediated oxygen delivery to intracellular mitochondria is demonstrated in cardiac myocytes isolated from the hearts of mature rats. Myocytes are held at high ambient oxygen pressure, 40-340 torr (5-45 kPa); sarcoplasmic myoglobin is fully oxygenated. In this condition oxygen availability does not limit respiratory rate; myoglobin-facilitated diffusion contributes no additional oxygen flux and, since oxygen consumption is measured in steady states, the storage function of myoglobin vanishes. Carbon monoxide, introduced stepwise, displaces oxygen from intracellular oxymyoglobin without altering the optical spectrum of the largely oxidized intracellular mitochondria. A large part, about one-third, of the steady-state oxygen uptake is abolished by carbon monoxide blockade of myoglobin oxygenation. The myoglobin-dependent component of the oxygen uptake decreases linearly with decreasing fraction of intracellular oxymyoglobin, with a slope near unity. Studies using inhibitors of mitochondrial electron transport indicate that myoglobin-delivered oxygen uptake depends on electron flow through the mitochondrial electron transport chain. We conclude that cardiac mitochondria accept two additive simultaneous flows of oxygen: a flow of dissolved oxygen to cytochrome oxidase and a flow of myoglobin-bound oxygen to a mitochondrial terminus. Myoglobin-mediated oxygen delivery supports ATP generation by heart cells at physiological ambient oxygen pressure.
Full text
PDF




Images in this article
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Bergersen F. J., Turner G. L., Appleby C. A. Studies of the physiological role of leghaemoglobin in soybean root nodules. Biochim Biophys Acta. 1973 Jan 18;292(1):271–282. doi: 10.1016/0005-2728(73)90271-5. [DOI] [PubMed] [Google Scholar]
- Clark A., Jr, Clark P. A., Connett R. J., Gayeski T. E., Honig C. R. How large is the drop in PO2 between cytosol and mitochondrion? Am J Physiol. 1987 Jun;252(6 Pt 1):C583–C587. doi: 10.1152/ajpcell.1987.252.6.C583. [DOI] [PubMed] [Google Scholar]
- Cole R. P. Skeletal muscle function in hypoxia: effect of alteration of intracellular myoglobin. Respir Physiol. 1983 Jul;53(1):1–14. doi: 10.1016/0034-5687(83)90012-9. [DOI] [PubMed] [Google Scholar]
- Cole R. P., Sukanek P. C., Wittenberg J. B., Wittenberg B. A. Mitochondrial function in the presence of myoglobin. J Appl Physiol Respir Environ Exerc Physiol. 1982 Nov;53(5):1116–1124. doi: 10.1152/jappl.1982.53.5.1116. [DOI] [PubMed] [Google Scholar]
- Degn H., Wohlrab H. Measurement of steady-state values of respiration rate and oxidation levels of respiratory pigments at low oxygen tensions. A new technique. Biochim Biophys Acta. 1971 Sep 7;245(2):347–355. doi: 10.1016/0005-2728(71)90153-8. [DOI] [PubMed] [Google Scholar]
- Driedzic W. R. The fish heart as a model system for the study of myoglobin. Comp Biochem Physiol A Comp Physiol. 1983;76(3):487–493. doi: 10.1016/0300-9629(83)90451-6. [DOI] [PubMed] [Google Scholar]
- Gayeski T. E., Honig C. R. O2 gradients from sarcolemma to cell interior in red muscle at maximal VO2. Am J Physiol. 1986 Oct;251(4 Pt 2):H789–H799. doi: 10.1152/ajpheart.1986.251.4.H789. [DOI] [PubMed] [Google Scholar]
- Giardina B., Amiconi G. Measurement of binding of gaseous and nongaseous ligands to hemoglobins by conventional spectrophotometric procedures. Methods Enzymol. 1981;76:417–427. doi: 10.1016/0076-6879(81)76133-0. [DOI] [PubMed] [Google Scholar]
- Gill S. J. Measurement of oxygen binding by means of a thin-layer optical cell. Methods Enzymol. 1981;76:427–438. doi: 10.1016/0076-6879(81)76134-2. [DOI] [PubMed] [Google Scholar]
- Hatefi Y., Galante Y. M. Isolation of cytochrome b560 from complex II (succinateùbiquinone oxidoreductase) and its reconstitution with succinate dehydrogenase. J Biol Chem. 1980 Jun 25;255(12):5530–5537. [PubMed] [Google Scholar]
- Katz I. R., Wittenberg J. B., Wittenberg B. A. Monoamine oxidase, an intracellular probe of oxygen pressure in isolated cardiac myocytes. J Biol Chem. 1984 Jun 25;259(12):7504–7509. [PubMed] [Google Scholar]
- Kawashiro T., Nüsse W., Scheid P. Determination of diffusivity of oxygen and carbon dioxide in respiring tissue: results in rat skeletal muscle. Pflugers Arch. 1975 Sep 9;359(3):231–251. doi: 10.1007/BF00587382. [DOI] [PubMed] [Google Scholar]
- King T. E. Cardiac cytochrome c1. Adv Enzymol Relat Areas Mol Biol. 1983;54:267–366. [PubMed] [Google Scholar]
- Li Y., Leonard K., Weiss H. Membrane-bound and water-soluble cytochrome c1 from Neurospora mitochondria. Eur J Biochem. 1981 May;116(1):199–205. doi: 10.1111/j.1432-1033.1981.tb05319.x. [DOI] [PubMed] [Google Scholar]
- Mahler M., Louy C., Homsher E., Peskoff A. Reappraisal of diffusion, solubility, and consumption of oxygen in frog skeletal muscle, with applications to muscle energy balance. J Gen Physiol. 1985 Jul;86(1):105–134. doi: 10.1085/jgp.86.1.105. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Palmer J. W., Tandler B., Hoppel C. L. Biochemical properties of subsarcolemmal and interfibrillar mitochondria isolated from rat cardiac muscle. J Biol Chem. 1977 Dec 10;252(23):8731–8739. [PubMed] [Google Scholar]
- Pattengale P. K., Holloszy J. O. Augmentation of skeletal muscle myoglobin by a program of treadmill running. Am J Physiol. 1967 Sep;213(3):783–785. doi: 10.1152/ajplegacy.1967.213.3.783. [DOI] [PubMed] [Google Scholar]
- Reddy K. V., Hendler R. W. Complete analysis of the cytochrome components of beef heart mitochondria in terms of spectra and redox properties. The b-type cytochromes. J Biol Chem. 1983 Jul 25;258(14):8568–8581. [PubMed] [Google Scholar]
- Riccio P., Schägger H., Engel W. D., Von Jagow G. bc1-Complex from beef heart. One-step purification by hydroxyapatite chromatography in Triton X-100, polypeptide pattern and respiratory chain characteristics. Biochim Biophys Acta. 1977 Feb 7;459(2):250–262. doi: 10.1016/0005-2728(77)90026-3. [DOI] [PubMed] [Google Scholar]
- STRITTMATTER P. The nature of the heme binding in microsomal cytochrome b5. J Biol Chem. 1960 Aug;235:2492–2497. [PubMed] [Google Scholar]
- STRITTMATTER P., VELICK S. F. The isolation and properties of microsomal cytochrome. J Biol Chem. 1956 Jul;221(1):253–264. [PubMed] [Google Scholar]
- Spatz L., Strittmatter P. A form of cytochrome b5 that contains an additional hydrophobic sequence of 40 amino acid residues. Proc Natl Acad Sci U S A. 1971 May;68(5):1042–1046. doi: 10.1073/pnas.68.5.1042. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Tamura M., Araki R., Ishikawa T., Sagisaka K., Yamazaki I. Direct observation of reduction of met- and ferrylmyoglobins in the hemoglobin-free perfused rat heart. J Biochem. 1980 Oct;88(4):1211–1213. doi: 10.1093/oxfordjournals.jbchem.a133077. [DOI] [PubMed] [Google Scholar]
- Taylor D. J., Matthews P. M., Radda G. K. Myoglobin-dependent oxidative metabolism in the hypoxic rat heart. Respir Physiol. 1986 Mar;63(3):275–283. doi: 10.1016/0034-5687(86)90095-2. [DOI] [PubMed] [Google Scholar]
- Weiss H., Kolb H. J. Isolation of mitochondrial succinate: ubiquinone reductase, cytochrome c reductase and cytochrome c oxidase from Neurospora crassa using nonionic detergent. Eur J Biochem. 1979 Aug 15;99(1):139–149. doi: 10.1111/j.1432-1033.1979.tb13240.x. [DOI] [PubMed] [Google Scholar]
- Wittenberg B. A., Robinson T. F. Oxygen requirements, morphology, cell coat and membrane permeability of calcium-tolerant myocytes from hearts of adult rats. Cell Tissue Res. 1981;216(2):231–251. doi: 10.1007/BF00233618. [DOI] [PubMed] [Google Scholar]
- Wittenberg B. A., White R. L., Ginzberg R. D., Spray D. C. Effect of calcium on the dissociation of the mature rat heart into individual and paired myocytes: electrical properties of cell pairs. Circ Res. 1986 Aug;59(2):143–150. doi: 10.1161/01.res.59.2.143. [DOI] [PubMed] [Google Scholar]
- Wittenberg B. A., Wittenberg J. B., Caldwell P. R. Role of myoglobin in the oxygen supply to red skeletal muscle. J Biol Chem. 1975 Dec 10;250(23):9038–9043. [PubMed] [Google Scholar]
- Wittenberg B. A., Wittenberg J. B. Oxygen pressure gradients in isolated cardiac myocytes. J Biol Chem. 1985 Jun 10;260(11):6548–6554. [PubMed] [Google Scholar]
- Wittenberg J. B. Facilitated oxygen diffusion. The role of leghemoglobin in nitrogen fixation by bacteroids isolated from soybean root nodules. J Biol Chem. 1974 Jul 10;249(13):4057–4066. [PubMed] [Google Scholar]
- Wittenberg J. B. Myoglobin-facilitated oxygen diffusion: role of myoglobin in oxygen entry into muscle. Physiol Rev. 1970 Oct;50(4):559–636. doi: 10.1152/physrev.1970.50.4.559. [DOI] [PubMed] [Google Scholar]
- Yu C. A., Yu L., King T. E. Soluble cytochrome b-c1 complex and the reconstitution of succinate-cytochrome c reductase. J Biol Chem. 1974 Aug 10;249(15):4905–4910. [PubMed] [Google Scholar]
- von Jagow G., Link T. A. Use of specific inhibitors on the mitochondrial bc1 complex. Methods Enzymol. 1986;126:253–271. doi: 10.1016/s0076-6879(86)26026-7. [DOI] [PubMed] [Google Scholar]

